1. Field of the Invention
This invention pertains to exercise apparatus which is in the form of a trainer that provides a simulated walking or running stride. The trainer of this invention falls within the field of exercise devices such as stepping machines, simulated cross country ski machines, stationary bicycles, as well as other types of exercise trainers. It more particularly relates to those types of exercise trainers within the art and background related to pedals that can be reciprocated as attached to a pair of cranks to provide for a simulated walking or running motion. In particular, it relates to those training and exercise devices which approximate an elliptical motion with respect to a user's foot movements.
2. Prior Art
Exercise and training devices come in many forms. As is generally known, such exercise devices can include stationary bicycles such as those of the reclining and vertical type. Further to this extent, there are such devices that are simulated stepping machines which allow one to step upwardly and downwardly to simulate a climbing of stairs. Also well known are treadmills that simulate running, jogging, and walking vigorously.
There are other well known devices that not only include cycling but also efforts related to treadmill workouts.
Treadmills generally permit a user to walk, jog or run on a stationary machine. However, they are considered impact devices which in some cases are not as beneficial to the user as for example a low impact device such as a bicycle whether it be a reclining or vertical bicycle or such stepping machines as are known in the art.
There are exercise trainers that are currently known in the art that simulate a running, walking, or jogging effort on a pair of pedals. These pedals are physically connected to cranks that are under a load.
It is preferable, that such exercise trainers have their pedals trace a path approximating an ellipse or what can be considered as a modified elliptical path. One of the drawbacks of such modified elliptical paths is that the major axis of the path is limited to being shorter than twice the crank's length. This is due to the fact that the axis of the crank as it turns a wheel or other device when considered with the axis of the connection at the end of the crank limits the overall stroke distance which forms the major axis of the modified elliptical path to that distance minus the axial orientations.
For example to achieve a sixteen inch length in the major axis of an elliptical like trainer, such cranks of a trainer need to have a longer crank length than half the length which would be eight inches. This takes into account the journaling and bearing mountings. From a practical standpoint in order to provide a sixteen inch length of the major axis of the modified elliptical path, a nine inch long crank must be utilized to provide approximately an eighteen inch diameter circle.
When the foregoing translates to the diameter of the wheel or disk under load that is being driven, it creates a significantly high pedal step up. In effect, to move or run at a sixteen inch stride even with such a large diameter disk or wheel utilizing the nine inch long crank shaft, the effect is that of a diminished step that could be analogized to a "baby step". It has been found in the past that this did not provide sufficient aerobic effort nor provide for enough hip flexure to maximize a cardiovascular workout through the leg, hip, quadriceps, and other muscle portions of the body.
Much of the prior art relies upon foot pedals that rigidly attach to foot links. These foot links are generally in connected relationship to the ends of the cranks. Usually there is little or no relative motion between the foot pedals and the foot links. This serves to limit the major axis as to the length of the major axis of the modified elliptical path inscribed by the foot pedal.
In order to overcome the deficiencies of the prior art, this invention utilizes a unique relative motion concept with respect to the foot links and the foot pedals. The invention in order to accomplish this, utilizes a foot pedal mounted with rollers on the foot link. The foot pedals are oriented with the foot links by means of these rollers which travel in a concave channel along the length of the foot link. This traveling of the rollers in the concave channels allows relative motion when the foot pedal has been maintained by a relationship to a ground or non-moving portion. The foot pedal moves in relationship to a fixed or grounded area such as to the frame.
In order to maintain this relative movement relationship, a flexible belt like element that can be in the form of a belt, chain, cable, or other member allows the foot pedal to slide relative to the foot link as the foot link reciprocates backwardly and forwardly. In effect, the flexible member pulls the foot pedal relative to the foot link in the direction of foot link travel. The net effect is to increase the stride length by a factor of four. The normal relative movement would be two times the crank length.
The net result of the foregoing is to create a movement whereby the foot links with the flexible member when moving backwardly cause a pulling of the foot pedals backwardly along the length of the foot link. This creates a stride with a modified elliptical motion while at the same time maintaining a small crank diameter such that the major axis of the modified ellipse is four times the length of the crank.
As will be seen hereinafter, this invention is a significant step over the art and can be modified by various belt or flexible member orientations with regard to the ground and the flexible member as well as the movement of the foot link.